Question

The energy bands are present only when the substance is present in the solid state.

• A. True
• B. False

Answer 1

The correct option is A True

This is because in a solid, there are several atoms placed closely together. The energy levels of inner orbit electrons of an atom are not influenced by the neighboring atoms as these electrons are tightly bound to their parent nucleus.
However, energy levels of outer orbit electrons of an atom are altered as these are influenced by the neighboring atoms. Therefore, the energy levels corresponding to outer shell electrons are spread up to form a band of energy. Therefore, the closely spaced energy levels of atoms in the solid combine to form an energy band.